With just a week until voting day, Stephen Harper spent Thanksgiving Monday defending Conservative seats in Ontario, while Justin Trudeau was in Ottawa making a pitch for disaffected Tories, and Tom Mulcair campaigned in B.C. to overcome his apparent slide in support.

Harper spent the day rallying supporters in Kitchener-Waterloo, where the Conservatives won all three ridings in 2011. (A fourth riding has since been added.)

Pollster Nik Nanos said that the Conservative strategy at this point should be "to stay in current Conservative ridings in order to try to hold on to as many as possible."

Sources tell CTV News the Tories are at risk of losing a dozen seats in Ontario, including those held by Immigration Minister Chris Alexander, Parliamentary Secretary Paul Calandra, Assistant Defence Minister Julian Fantino and Finance Minister Joe Oliver.

And the latest Nanos Research polling for CTV News and the Globe and Mail has the Liberals at 45 per cent, the Conservatives at 33 per cent and the NDP at 18 per cent in Ontario, based on 325 decided individuals. (A sample of 325 is accurate ±5.5 percentage points, 19 times out of 20.)

Harper took aim at Trudeau during his speech in Kitchener, warning that the average Canadian family would lose thousands of dollars if the Liberals are elected.

To further his point, a sign was posted on Harper's podium reading "The Cost of Liberal Tax Hikes," with a breakdown of the added taxes the Tories say a Liberal government will enact posted below.

A local family was invited onstage to help highlight this point, with the mother of the family placing piles of money on a table, and the sound of a cash register going off in the background.

After the rally, Harper dismissed questions over the latest polls. Nationally, the Liberals in the lead with 36 per cent support, followed by the Conservatives at 29 per cent and the NDP at 24 per cent.

"Polls are all over the map," Harper said, adding that the majority of Canadians have not yet voted. "Polls don't decide the election, voters do."

Both the Liberal and NDP leaders have said they wouldn’t prop up the Tories in Parliament, if the Conservatives were to win a minority government. When asked to respond to these promises from his opponents, Harper again declined.

"Canadians will make a choice," he said. "The choice is fundamentally about the economy. Do we want to keep growing the economy, keep creating jobs, (and) keep delivering benefits to people that we can afford? That's what we're running on."

Trudeau appeals to Tory voters

Trudeau made an appeal to Tory voters in Nepean, Ont., arguing that the Conservative Party under Harper's leadership has lost sight of the party's values.

The Liberal leader said past Progressive Conservative governments have a "proud history" in Canada. But under Harper's leadership the party has become focused on "wedge politics.”

"I believe that a prime minister should never try and win votes by pitting Canadians against one another or by provoking fear and division," he said.

Trudeau added that Conservatives “aren’t our enemies,” and that “they want what’s best for their country -- just like we do.”

"They want safe communities and a growing economy, they want better jobs and more opportunities for their kids," Trudeau went on. "They want their country to stand for something in the world, with the tenacity to solve big problems."

Trudeau re-emphasized his pledge to bring "real change" to the country, and help grow the middle class. He said, if elected, the Liberals will introduce a tax cut for the middle class as its very first bill.

The Liberal leader was asked why he hasn't been returning calls from NDP Leader Thomas Mulcair, who said he's been trying to contact Trudeau to discuss what might happen if the Conservatives win a minority government.

Trudeau declined to give a specific answer, instead accusing the NDP leader of changing his position on policies depending on what the polls show.

"One of the things we've seen from Mr. Mulcair over the past six months, is depending on what the polls are doing, he is saying different things at different points," Trudeau said.

"I have been very, very clear. I am focused on putting forward a strong and clear vision for this country based on a real plan for change."

Mulcair campaigns in B.C.

With support eroding in Ontario, Tom Mulcair campaigned in B.C., where his party is polling much closer to the Liberals and Conservatives.

Nanos has the Conservatives and Liberals tied for first place in B.C. with 29 per cent each, followed by the NDP at 25 per cent and the Greens at 15 per cent, based on 169 decided people. (A sample of 169 respondents is accurate ±7.6 percentage points, 19 times out of 20.)

Mulcair told a crowd in Maple Ridge, B.C., that the NDP is the best bet to defeat the Conservatives.

The NDP leader pointed out that his party only needs to add 35 seats to form government. By comparison, the Liberals will need to elect more than 100 additional MPs to defeat the Tories.

Mulcair again accused the Conservatives of negotiating the Trans-Pacific Partnership trade deal in "secret" and accused Trudeau of siding with Harper on the TPP deal.

The NDP leader deflected questions about his party's recent slide in the polls, insisting that the election is still a three-way race.

"I know the NDP is offering hope -- hope to break an old habit that's been in place for 140 years -- when you're fed up with the Conservatives, you're forced to go back to the Liberals," Mulcair said, adding that this isn't the case for this election.

"For the first time in the history of Canada, there is a three-way race."

With reports from CTV’s Robert Fife, Laurie Graham and Richard Madan, and files from The Canadian Press